DE102013211929B4 - Engine starting procedure - Google Patents

Abstract

A method of starting an engine (10) having a fuel rail (16) comprising: detecting a triggering event, monitoring a start request of an operator, monitoring a pressure in the fuel rail (16), a camshaft (20) of the engine Engine (10) is oscillated with a cam phaser (24), wherein the camshaft (20) does not perform a complete rotation during the oscillation; a fuel rail pump (30) is operated with the oscillating camshaft (20) until the monitored pressure in the fuel rail ( 16) reaches a minimum level; andthe engine (10) is started after the monitored pressure reaches the minimum level and a start request of the operator is present, characterized in that, if no start request of the operator has occurred, and after the minimum level is reached: the fuel rail pump (30) the oscillating camshaft (20) is operated until the monitored pressure in the fuel rail (16) reaches a target level, the target level being greater than the minimum level; andthe engine (10) is started after the monitored pressure reaches the target level and a start request of the operator is present.

Description

TECHNICAL AREA

This disclosure relates to starting methods for internal combustion engines.

BACKGROUND

Direct injection is a variant of fuel injection used in internal combustion engines. The fuel is pressurized and injected by means of a common rail and a fuel injector directly into the combustion chamber of each cylinder, as opposed to a conventional multi-point fuel injection which takes place in the intake stroke or in a cylinder port.

From the JP 2007-077904 A a method according to the preamble of claim 1 is known.

An object of the invention is to provide a method for starting an internal combustion engine, with which a delay between a start request of an operator and an actual start of the engine is avoided.

SUMMARY

This object is achieved by a method having the features of claim 1 or 7.

A method is provided for starting an engine with a fuel rail. The method includes detecting a triggering event and monitoring a pressure in the fuel rail. A camshaft of the engine is oscillated with a cam phaser. During the oscillation, the camshaft does not perform complete rotation. A fuel rail pump operates on the oscillating camshaft until the monitored pressure in the fuel rail reaches a minimum level. After the monitored pressure reaches the minimum level, the engine is started when there is a start request of an operator of the vehicle.

list of figures

• 1 is a schematic representation of an engine with a fuel rail; and
• 2 FIG. 10 is a schematic flowchart illustration of a method 100 for starting an engine.

DETAILED DESCRIPTION

With reference to the drawings, like reference numerals correspond to like or similar components throughout the various figures wherever possible. 1 shows a highly schematic diagram of an engine 10 which can be used with some of the methods, such as the method 100 from 2 described herein.

The engine shown 10 is for illustration purposes only, it can have many additional components, and it can perform many additional functions. The motor 10 has a block 12 with one or more piston cylinders 14, of which three in 1 are shown. The motor 10 takes power from combustion processes that occur in the piston cylinders 14 occur.

A fuel rail 16 leads the piston cylinders 14 Fuel too. In a training of the engine 10 will the piston cylinders 14 Fuel supplied by a direct injection, and the engine 10 can be a spark-ignition engine with direct injection (SIDI engine). As described herein, the fuel rail provides 16 pressurized fuel to the fuel injectors (not shown).

A crankshaft 18 receives power from the engine 10 and outputs the power to the rest of the powertrain, such as via a transmission (not shown). Inlet and exhaust functions as well as the timing of the piston cylinders 14 Partially through one or more camshafts 20 controlled, of which only one in 1 is shown.

The crankshaft 18 and the camshaft 20 are through a time setting mechanism 22 connected without limitation: belts and pulleys, sprockets and chains, gears or combinations of these. At least one cam phaser 24 provides a variable timing between the crankshaft 18 and the camshafts 20 ,

Therefore, the camshafts 20 during operation of the engine 10 a variable timing relative to the crankshaft 18 exhibit what the performance characteristics of the engine 10 can improve. As used herein, the engine is 10 "In operation" when the engine 10 was started and a combustion in the piston cylinders 14 occurs, so the piston cylinders 14 Fuel is supplied and the spark ignition system ignites. Note, however, that much of the discussion herein relates to time periods while that of the engine 10 is not in operation and does not fire.

A fuel tank 26 supplies fuel to the fuel rail 16 , A fuel rail pump 30 puts the fuel in the fuel rail 16 under Print. The fuel rail pump 30 may be in addition to a fuel pump (not shown) in the fuel tank 26 operate. The fuel rail pump 30 is functional with the camshaft 20 Connects and converts kinetic energy of the rotating camshaft 20 in an increased pressure of the fuel around, which is the fuel rail 16 is supplied.

If the engine 10 is operating, operates the rotating camshaft 20 the fuel rail pump 30 , The camshaft 20 revolves under the force caused by the timing mechanism 22 and the crankshaft 18 is delivered to valves to the piston cylinders 14 to open and close. The fuel rail pump 30 in the engine 10 However, it is also designed to be operated even when the camshaft 20 not turning - ie, when the camshaft 20 does not perform full turns.

The phaser 24 may be an electrically driven cam phaser, so that it is formed to the camshaft 20 over its full range of cam variability relative to the crankshaft 18 to move when the engine 10 is in operation or is not in operation. Other types of cam phasers - such as fluid driven phasers - may be used with the phaser 24 used as long as the phaser 24 is capable of the camshaft 20 to move when the engine 10 not in operation.

When the camshaft 20 by a force from the phaser 24 is oscillated backwards and forwards, is the fuel rail pump 30 formed, at least a small pump stroke of the camshaft 20 take. The cams of the camshaft 20 either those used to operate the valves or a separate cam - act as a piston (not shown) of the fuel rail pump 30 , Therefore, the fuel rail pump continues 30 the fuel for the fuel rail 16 under pressure when the camshaft 20 oscillates, but does not turn.

The piston of the fuel rail pump 30 allows fuel to be drawn into a pumping chamber (not shown) during a return stroke. The fuel is then pressurized during a compression stroke. The pressurized fluid becomes the fuel rail 16 fed, where the pressure is accumulated. Some forms of fuel rail pump 30 may include one or more electromagnets (not shown) for communicating the inlet of fuel into the pumping chamber, the outlet of fuel to the fuel rail 16 or both. The amount of fuel pumped, the pressure that is dissipated, or a combination of both generally increases with the stroke distance with which the cams of the camshaft 20 on the piston of the fuel rail pump 30 act.

A control system or a controller 32 monitors and controls some or all of the components of the engine 10 including those discussed herein and others. The controller 32 may include one or more components having a storage medium and a suitable size of programmable memory capable of storing and executing one or more algorithms or methods to control the motor 10 and possibly other components of the vehicle. The controller 32 can be related to numerous sensors and communication systems of the vehicle. Each component of the controller 32 can be a distributed architecture for the controller 32 include, such as a microprocessor-based electronic control unit (ECU) or an engine control module (ECM). Additional modules or processors may be in the controller 32 be present, and the controller 32 may only be part of a powertrain control module (PCM) or other control system.

The motor 10 may be configured to perform auto-stop auto-start events. The controller 32 can determine that the vehicle has been stopped - for example at a red traffic light - and the engine 10 automatically turn off (an auto-stop event or an auto-stop command) until the vehicle is ready to move again, at which point the controller 32 the engine 10 automatically starts (an autostart event or an autostart command). The motor 10 can also be a starter 34 configured to cause the starting events, such as cold starts or auto-starting by the crankshaft 18 is turned.

In some training, the starter 34 or the crankshaft 18 be formed to the position of the crankshaft 18 to investigate. In combination with the state of the phaser 18 can the position of the camshaft 20 can be determined - alternatively, a sensor, the position of the camshaft 20 determine directly.

Because the camshaft 20 not completely rotates while the engine 10 is not in operation, such as during an oscillation of the camshaft 20 to the fuel rail pump 30 To operate, the effectiveness of the fuel rail pump 30 depend on the position of the camshaft. That is, the backward and forward oscillation of the camshaft 20 depending on the location of the cam relative to the pump piston leads to a different size of the stroke. Therefore, the starter 34 used to position the crankshaft 18 and the camshaft 20 easy to change the cam of the camshaft 20 in an improved position for the stroke of the pump piston of the fuel rail pump 30 bring to.

Now up 2 Referring to and with further reference to 1 is an illustrative flowchart of the method 100 shown. For illustrative purposes, the method may be 100 can be described with reference to the elements and components shown and described in the figure, and it can by the motor 10 or through the controller 32 be executed. However, other components can be used to complete the process 100 and to practice the invention as defined in the appended claims.

Names, titles or descriptions of steps are provided to aid in the coordination between the detailed description and the flowchart, but not for the purpose of limitation. Any of the steps may be performed by multiple controllers or control system components. The procedure 100 Can be used on engines and powertrains with different designs.

step 110 : Start / Start.

The procedure 100 may begin at a start or initialization step during which the method 100 is activated. Starting the procedure 100 may occur in response to the operating conditions of the vehicle or engine 10, or it may be assumed that the method 100 is constantly in operation, so the procedure 100 starts when mounting the vehicle. The procedure 100 can be constant, iterated or executed in a loop.

step 112 : Detecting a trigger.

The procedure 100 includes detecting a triggering event. The occurrence of the triggering event indicates an imminent need or predicted need for the engine 10 to start. In many cases, the trigger event occurs before a start request of an operator, or it can be a predictor of the start request or a start command of an operator. The trigger event may include, without limitation, one or more of: an unlock command from a remote controller, such as a key fob; the start request of the operator, which can also be remotely sent from the key fob; a predetermined time of the day; a proximity sensor that determines that the operator is near the vehicle.

The vehicle may have an auto-stop auto-start technology, which is the engine 10 generally shuts off when the motor vehicle is not in motion or driven by other means, such as one or more electric motors. Autostop autostart can also be referred to as an idle-stop technology. For vehicles that have auto-stop autostart functionality, the trigger event may be an autostop command, so the procedure 100 as part of the auto-stop autostart works while the engine 10 not in operation.

step 114 : Monitor the Waist Pressure.

The procedure 100 includes that pressure in the fuel rail 16 is monitored. The power of the engine 10 or the vehicle in general can be improved when the pressure in the fuel rail 16 above the atmospheric pressure. The fuel rail 16 however, it may not be designed to sustain pressure while the engine is running 10 not in operation, since the fuel rail pump 30 may not work. Therefore, the pressure of the fuel in the fuel rail 16 begin to fall off after the engine 10 is shut down or otherwise inoperative.

step 116 : Has the pressure reached a minimum?

The procedure 100 Determines if the monitored pressure in the fuel rail 16 at or below a minimum level. It may be for the engine 10 be advantageous to start only after the minimum level has been reached. If the triggering event determines that the operator's startup request is imminent, the process begins 100 with it, the fuel rail 16 to pressurize before receiving the start request of the operator, so that a delay between the request and the actual start is reduced.

step 118 : Has a start command occurred?

The procedure 100 may include monitoring the start request of the operator. When the pressure in the fuel rail 16 at or above the minimum level, the process proceeds 100 determining if the operator's startup request has occurred or has been received. For vehicles with auto-stop autostart functionality, the operator startup request may be the autostart command.

step 120 : Igniting the engine.

When the monitored pressure reaches the minimum level and the operator startup request has occurred, the process proceeds 100 with the start of the engine 10 Ahead. This can be a cold start of the engine 10 be when the engine 10 was not in operation for a significant amount of time, or an auto start of the engine 10.

step 122 : Oscillating the camshaft.

If the monitored pressure is less than the minimum level, the process begins 100 , the camshaft 20 of the motor 10 to oscillate with the cam phaser 24. The camshaft 20 however, does not perform complete rotation during the oscillation. The fuel rail pump 30 is operated by the camshaft 20 is oscillated and it creates the pressure in the fuel rail 16 ,

The procedure 100 may be formed such that the camshaft 20 continues to oscillate until the monitored pressure in the fuel rail 16 reached a minimum level. After the monitored pressure has reached the minimum level, the engine can 10 be started when the start request of the operator has occurred. The increased pressure in the fuel rail 16 compared to the atmospheric pressure can be the operation of the engine 10 improve.

step 123 : Adjusting the crankshaft position.

As an additional step before or simultaneously with the oscillation of the camshaft 20 can the procedure 100 the position of the crankshaft 18 to adjust. The pump stroke and the effectiveness during the oscillation of the camshaft 20 can from the location of the camshaft 20 depend. Therefore, the process can 100 the position of the camshaft 20 in a position for pumping the fuel rail pump 20 change.

By the position of the crankshaft 18 is set, the camshaft 20 be brought into a position (rotational position), which operates the fuel rail pump 30 better. The controller 32 can change the position of the crankshaft 18 and the camshaft 20 determine so that the fuel pressure can be amplified faster by the position of the camshaft 20 is adjusted so that the cams cause the piston of the fuel rail pump 30 generates more pressure during the oscillation. The ignition 34 Can be used to crankshaft 18 to rotate, which causes the timing mechanism 22 also the camshaft 20 rotates. Similar steps can be used to operate the fuel rail pump 30 during any of the camshaft oscillation procedures 20 described herein.

step 124 : Has the pressure reached a target value?

After the minimum level is reached, the process proceeds 100 then, if no start command has occurred, continue determining whether the monitored pressure in the fuel rail 16 at or has reached a target level. The target level is greater than the minimum level and it can be the operating conditions of the engine 10 continue to improve compared to the fuel pressure at the minimum level. For some trainings of the procedure 100 becomes the engine 10 started at any time independently of other objectives of the conditions when the fuel pressure is above the minimum level and the operator's start request has occurred.

step 126 : Oscillating the camshaft.

If the monitored pressure is less than the target level, the method 100 begins the camshaft 20 of the motor 10 with the cam phaser 24 to oscillate until the monitored pressure in the fuel rail 16 reached the target level. The procedure 100 may be performed in a loop and oscillate the camshaft 20 until the fuel pressure reaches the target level, or it may be configured with an operator intervening startup shutoff. Therefore, the process can 100 the engine 10 Start before the target level is reached, when the monitored pressure is above the minimum level and the start request of the operator takes place.

step 128 : Has a start command occurred?

After the target level of fuel pressure in the fuel rail 16 reached, determines the method 100 whether the start request of the operator has been made or received. The procedure 100 starts the engine 10 when the start request of the operator has been received.

This can be a cold start of the engine 10 be when the engine 10 for a significant period of time was not running, or an auto start of the engine 10 , Regardless of whether the start event is a cold start or an auto start of the engine 10 is the increased fuel pressure in the fuel rail 16 to provide improved engine performance, especially during the first cycles of operation.

step 130 : Hold between target value and maximum.

After the target level is reached, the procedure goes 100 into a hold function if no start request has been made by the operator. The procedure 100 operates the fuel rail pump 30 with the oscillating camshaft 20 until the monitored pressure in the fuel rail 16 reaches a maximum level greater than the target level. After the maximum level is reached, the process stops 100 the fuel rail pump 30 so that it does not increase the fuel pressure beyond the maximum level.

The procedure 100 starts again, the fuel rail pump 30 with the oscillating camshaft 20 to operate when the monitored pressure in the fuel rail 16 falls below the target level. Therefore, the monitored pressure is maintained substantially between the target level and the maximum level. Alternatively, the fuel rail pump 30 be periodically switched on and off to prevent the fuel pressure drops significantly below the maximum pressure. The procedure 100 may continue to hold the fuel pressure between the target level and the maximum level until the operator's start request is received, at which point the procedure 100 the engine 10 starts.

As an optional process within the process 100 or simultaneously with this, an immediate crankshaft start (in 2 not shown). The immediate crankshaft start may be executed when the operator's start request is received before the pressure in the fuel rail 16 reaches the minimum pressure. This can occur if the triggering event does not occur at all, or if the triggering event occurs, but it is very closely followed by the operator's startup request.

For example, and without limitation, if the triggering event occurs and immediately follows the operator's startup request, then the method is unlikely to occur 100 is capable of the camshaft 20 to oscillate for a sufficient amount of time to raise the fuel pressure above the minimum. Instead of waiting for the oscillation to increase fuel pressure, the controller can 32 instruct that the starter 34 that starts the engine 10 crank (ie, the crankshaft 18 to turn completely). Turning the crankshaft 18 causes the camshaft 20 completely rotates and the fuel pump 30 operates - with the full pump stroke - and the pressure in the fuel rail 16 elevated.

After the immediate crankshaft start is executed, the controller can 32 start the cylinders 14 Supplying fuel and supplying it with a spark. Alternatively, the controller 32 the fuel supply and the ignition delay until the complete rotation of the crankshaft 20 causes the pressure in the fuel rail 16 reached the minimum pressure. Note that if the immediate crankshaft start delays the ignition, the operator has some delay between the start request and the actual start of the engine 10 can notice. This delay does not occur when the procedure 100 detects the triggering event and has time to move the camshaft 20 to oscillate and the pressure in the fuel rail 16 to increase above the minimum pressure before the start request of the operator is received.

Claims (8)

A method of starting an engine (10) having a fuel rail (16), comprising: detecting a triggering event; a start request of an operator is monitored; a pressure in the fuel rail (16) is monitored; a camshaft (20) of the engine (10) is oscillated with a cam phaser (24), wherein the camshaft (20) does not perform complete rotation during the oscillation; operating a fuel rail pump (30) with the oscillating camshaft (20) until the monitored pressure in the fuel rail (16) reaches a minimum level; and the engine (10) is started after the monitored pressure reaches the minimum level and a start request of the operator is present, characterized in that when no start request of the operator has occurred and after the minimum level is reached: the fuel rail pump (30 ) is operated with the oscillating camshaft (20) until the monitored pressure in the fuel rail (16) reaches a target level, the target level being greater than the minimum level; and the engine (10) is started after the monitored pressure reaches the target level and a start request of the operator is present. Method according to Claim 1 further comprising that, after the target level is reached and when no operator startup request has occurred: the fuel rail pump (30) is operated with the oscillating camshaft (20) until the monitored pressure in the fuel rail (16) reaches a maximum level where the maximum level is greater than the target level; the fuel rail pump (30) is stopped; the fuel rail pump (30), when the monitored pressure in the fuel rail (16) drops below the target level, is operated with the oscillating camshaft (20) such that the monitored one Pressure is kept substantially between the target level and the maximum level; and the engine (10) is started after the start request of the operator occurs. Method according to Claim 2 further comprising that the engine (10) is started before the target level is reached when: the monitored pressure is above the minimum level; and the start request of the operator occurs. Method according to Claim 3 wherein the trigger event is one of: an unlock command from a remote controller; and a predetermined time of the day. Method according to Claim 3 wherein the triggering event is an auto-stop command and the operator's startup request is an autostart command. Method according to Claim 2 wherein the engine (10) further comprises a starter (34) configured to rotate a crankshaft (18), and further comprising: determining a position of the crankshaft (18) or the camshaft (20); and rotating the crankshaft (18) to change the position of the camshaft (20) during or before oscillating the camshaft (20) with the cam phaser (24). A method of starting an engine (10) having a fuel rail (16), comprising: detecting a triggering event; a pressure in the fuel rail (16) is monitored; a start request of an operator is monitored; a camshaft (20) of the engine (10) is oscillated with a cam phaser (24), wherein the camshaft (20) does not perform complete rotation during the oscillation; operating a fuel rail pump (30) with the oscillating camshaft (20) until the monitored pressure in the fuel rail (16) reaches a minimum level; and the engine (10) is started after the monitored pressure reaches the minimum level and a start request of the operator is present, characterized in that when no start request of the operator has occurred and after the minimum level is reached: the fuel rail pump (30 ) is operated with the oscillating camshaft (20) until the monitored pressure in the fuel rail (16) reaches a target level, the target level being greater than the minimum level; and the engine (10) is started after the monitored pressure reaches the target level and a start request of the operator is present; and when no operator start request has occurred and after the target level is reached: the fuel rail pump (30) is operated with the oscillating camshaft (20) until the monitored pressure in the fuel rail (16) reaches a maximum level maximum level is greater than the target level; the fuel rail pump (30) is stopped; when the monitored pressure in the fuel rail (16) drops below the target level, the fuel rail pump (30) is operated with the oscillating camshaft (20) such that the monitored pressure is maintained substantially between the target level and the maximum level; and the engine (10) is started after a start request of the operator is present. Method according to Claim 7 wherein the trigger event is one of: an unlock command from a remote controller; and a predetermined time of the day.

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